Hi,
I was using the excellent ETTR module, and was wondering if the camera TTL light metering sensor could be used to calculate the exposure before taking the shot. I know that the metering sensor is very limited when compared to the full image sensor, but it has the advantage of being available before the shot.
Of course, i don't suggest to replace current functionality with this, but could be very interesting to have as an additional trigger mode.
It could also be used in any mode to decide the starting exposure parameters to use for the first shot or LV capture.
I mean, even if the metering sensor only has 63 zones (depending on camera model, of course), they cover the whole scene, so if the exposure parameters are chosen to avoid overexposure of the brightest zone, then the scene would be 100% ETTR, right? Probably an option to choose how many zones are allowed to be overexposed would be necessary, to account for specular lights.
Another configurable option that could be useful, is to use the spotmeter to set the ETTR limit, so that the photographer chooses what is the highest tone that shouldn't be clipped. So, you point the spotmeter at the brightest tone you want to capture, press SET, and the ETTR exposure time and ISO are calculated.
Thanks for such a great piece of software for our cameras!!
I often wonder why manufacturers themselves don't add such functions, considering that they already recognize that people do use RAW capture, and ETTR is the best way to capture data in RAW mode. Maybe they don't want the preview to look "overexposed", but it wouldn't look "overexposed" if they lower the exposure of the RAW data after capture to match whatever "standard" exposure they would have normally used, and then create the JPG from it.
But of course, they don't even show an histogram calculated from the RAW data when shooting RAW, for whatever incomprehensible reason. I suppose that they consider that their customers shooting RAW are a minority, and it doesn't justify the extra programming time :'(
Regards